V0.9.3.0 - Cleanup & Optimizations

• Modified README to explain ytAuto better.
• Added new arguments:

ytAuto                      # Updates all channels in parallel
ytAuto -h, --help           # Show help message with list of arguments
ytAuto -l, --list           # Lists all tracked channels
ytAuto -a URL, --append URL # Adds a new channel by URL (format: any yt-dlp supported links)
ytAuto -r URL, --remove URL # Removes a channel by URL (exact match required)
ytAuto -s URL, --single URL # Downloads a single channel immediately and adds it to tracking
ytAuto --log                # Displays the latest log entries (one per tracked channel)

• Limited number of processes spawned to number of processors on a machine to help with rate limits.
• Log now shows the number of videos downloaded:

BEFORE:
[00:03:15] [NEW] jawed: Content archived.
[00:03:17] [NEW] Servibes897: Content archived.

AFTER:
[00:03:15] [NEW] jawed: 1 video(s) archived.
[00:03:17] [NEW] Servibes897: 3 video(s) archived.

• Channels.list now takes channel_link,channel_directory format:

kended@MFDebian:~/Public/ytAuto$ ./ytAuto -a https://www.youtube.com/@jawed
Suggested directory name: jawed
Press Enter to accept, or type a new directory name: myFavoriteChannel

Updated List of Channels:
https://www.youtube.com/@jawed,myFavoriteChannel

This allows users to set custom names for video links they're archiving, or use nested directories to put multiple links in the same directory.
Ex: youtube.com/@jawed,~Other/jawed

• Refactored arg_parser.c